I think this is waaay into fanon territory regarding Dumbledore's supposed obsession with redeeming Death Eaters.
While Dumbledore spent six books talking up Snape and redemption to Harry, that was because Snape was his spy and to do otherwise would have compromised his most effective agent. Once we get Snape's PoV from the memories Harry collects as Snape dies, we discover that Dumbledore held Snape's actions and motivations in absolute contempt, going so far as to say, "You disgust me".
I believe this view of Dumbledore's supposed overly forgiving nature comes from his revulsion at the idea of killing; a revulsion that is fully justified in setting. We know that in the Potterverse, killing a person literally damages the killer's soul. This is why murder is a step in the creation of a horcrux; the maker has to damage their soul in order to remove a piece while the damage is still fresh.
Killing a person is therefore provably wrong on a metaphysical level. Dumbledore's biggest hope seems to have been for Harry to live and die a natural life without having to take any lives in turn, as a counterpoint to Voldemort's unnatural life of repeated murders.
While Dumbledore spent six books talking up Snape and redemption to Harry, that was because Snape was his spy and to do otherwise would have compromised his most effective agent. Once we get Snape's PoV from the memories Harry collects as Snape dies, we discover that Dumbledore held Snape's actions and motivations in absolute contempt, going so far as to say, "You disgust me".
I believe this view of Dumbledore's supposed overly forgiving nature comes from his revulsion at the idea of killing; a revulsion that is fully justified in setting. We know that in the Potterverse, killing a person literally damages the killer's soul. This is why murder is a step in the creation of a horcrux; the maker has to damage their soul in order to remove a piece while the damage is still fresh.
Killing a person is therefore provably wrong on a metaphysical level. Dumbledore's biggest hope seems to have been for Harry to live and die a natural life without having to take any lives in turn, as a counterpoint to Voldemort's unnatural life of repeated murders.
“I really hope I’m behind this convoluted mess; at least that way I’ll be able to get revenge by doing this to myself. I won’t even have to feel bad because it’ll be all my fault.” - Harry Potter, The Master of Death by Ryuugi.